Speed-responsive device



June 5, 1951 G. T. RANDOL Re. 23,375

SPEED RESPONSIVE DEVICE 2 Sheets-Sheet 1 Original Filed Jan. 5, 1946 /IIIIIIIIII;II

.l/IS Afro June 5, 1951 a. 'r. RANDOL 23,375

SPEED RESPONSIVE DEVICE Original Filed Jan. 5, 1946 2 Sheets-Sheet 2 mz vk -which will be free from the predetermined value and so designed as Reiuued June 5, 1951 UNITED STATES PATENT OFFICE 23,375 SPEEDV-RESPONSIVE DEVICE Glenn '1. Randal, Mountain Lake Park, Md., as-

signor of one-half 1101, Mountain OrigilIl-l No.

Serial No. 639,184,

tion for reissue March 23,

18 Claims.

Matter enclosed reissue specification; matter printed in italics in This invention One of the objects of my invention is to provide 7 an improved speed -responsive device for actuating a control member from one operative position to another when the speed of a. member thereof assumes a predetermined value.

Another object is to produce an. improved speed responsive device having centrifuge members which are capable of causing limited positive moving of a control member from one operative position toward another when a predetermined speed is attained by its rotating member.

A further object related to that last stated is to associate with such a member an over-center spring means operable for completing the final movements of said member to either of its two difierent operative positions.

A still further object is to provide an improved speed-responsive means for controlling the moving of a control member from one operative position to another without lag when the speed of a member assumes a predetermined value.

Yet another object is to provide improved speed-responsive controlled means for moving a control element from one operative position to another when a predetermined speed is attained hunting" in the event the speed should vary within limits on each side ment has been caused to assume its said other operative position.

A more specific object is to provide in a speedresponsive device rotatable cam means for 61- to Elizabeth Leighton Ralllake Park, M11.

2,534,133, dated December January 5, 1946.

19, 1950, Applica- 1951, Serial No.

(Cl. 'M25) in heavy brackets appears in the original patent but forms no part of this dicates the additions made by reissue.

after the control elerectly' initiating the movement of a control elesustained periodsand thus eliminate the 'neces- Y sity of using relay switches in the circuits controlled by said switch element.

Yet a further object is to produce a speedresponsive device which is sensitive in its settings to be regulated by a single adjusting means to vary the predetermined speed at which it' is capable of establishing difierent' operative conditions.

device having centrifuge but showing the switch A further object is to produce a speed-sensitive members which is so designed that the centrifuge members are not required to overcome any resis nce by the action of centrifugal force to obtain changed operating conditions.

A further object'is to produce an improved I speed-responsive device for controlling a predetermined movement of an element toward dinerent positions which will embody centrifuge members movable to select said movement by variable speeds of a rotating member, and wherein said rotating member will produce all the torque force necessary to move the element aforesaid without any resistance opposing the free action of the centrifuge members by the centrifugal and centripetal forces acting thereon to select said movement.

A still further object is to produce a speedresponsive device which is simple in design, easy to manufacture at a low cost and applicable to a wide range of uses in control systems.

Other objects of my invention will become apparent from the following description taken in connection with the accompanying drawings in which:

Figure 1 is a schematic view of a control system having associated therewith as one of the control units, a speed-responsive device embodying my invention, and employed to move a switch element to two different operative positions to establish different control circuits, non-energized circuits being indicated by broken lines;

Figures 2 and 3 views of the speed-responsive device, said views being taken on the lines 2-2 and 3-3, respectively, of Figure 1;

' Figure 4 is a horizontal sectional view showing the over-center spring actuated switch arm in its operative position of Figures 2 and 3, said sectional view being taken on the line 4-4 of Figure 2;

Figure 5 is a sectional view similar to Figure 3, but showing the parts in a different position resulting in the switch arm being moved to its other operative position;

Figure 6 is a. sectional view similar to Figure 4,

arm in the position assumed in Figure 5; v I

Figure '7 is an enlarged view, partly in section,

showing detail construction of parts of the switch arm and the actuating cam, together with their relationship to accomplish the over-center spring are difierent vertical sectional sponsive device is shown in Figure 1.

. fluid pressure system.

directly control a valve element instead of a switch element; and

Figure 9 is a sectional view taken on the line O! of Figure 8.

Referring to the drawings in detail and first to Figures 1 to .7, inclusive, wherein my improved speed-responsive device isshown as being'employed to control the closing of two switchesin two independent electrical circuits. {in example of the circuits to be controlled by the speed-re- In this figure my improved speed-responsive device or governor is indicated generally by the letter G' and the two switches to be controlled are indicated by the letters G and The switch G forms part of a circuit X and theswitch G forms part of a circuit Y. Within the circuit X is a solenoid S and within the circuit Y is a solenoid S, which solenoids will be energized whenever the circuits are closed. Both circuits are connected by a common conductor Cwhich is connected to a source of current such as the grounded battery B. In order to complete the circuits by alternate closing of switches G and G the common closing element of the speed-responsive device G (to be later described) is connected to ground by a conductor Z. If desired, the comthe circuits may have a switch W for maintaining both circuits open.

In the system shown, by way of example, the solenoid S is employed when energized to open a valve V of a fluid pressure system and the solenoid S when energized to open a valve V of the This fluid pressure system comprises a source of fluid pressure or vac uum P and a double acting fluid pressure operated motor M having an actuating piston A.

The source of pressure is connected to one end of the fluid motor M through the valve V by suitable piping L, as shown, and other piping L is employed to connect operate the fluid motor M notwithstanding that one or the other of the electrical circuits is energized due to the master switch W being closed.

When the solenoid S is energized by the closing of the switch G M with the source of pressure, and if this source of pressure is less than atmospheric pressure as, for example, a vacuum source, the piston A will be moved to the [lower] upper end of the fluid motor as illustrated in Figure 1. opening 01 the valve V de-ene gized as the circuit Y (shown in broken lines) will be opened by the switch G. This de-energization of the solenoid S will result in the valve V being closed so as to disconnect the source of pressure from the [upper] lower end of the fluid motor, [but will permit] and place this [upper] lower end [to be connected to] in commun cation with the atmosphere by the particular valve structure shown. With the [upper] end of the fluid motor mosphere, the piston [will be free] is freed to move to the [lower] upper end of the fluid motor as illustrated. Whenever the circuit X is broken by opening of the switch G be closed by the speed-responsive/device G and consequently the solenoid S will be de-energized and the solenoid S energized. This will result in the circuit X, the valve V will be opened so as to connect the fluid motor During the the solenoid S will be the source of pressure with the other end of the fluid motor through the engage a sleeve. I 2

connected to at-- the switch G will nor G for controllin the end of the fluid motor through If the source of pressure should be super-atmospheric, then the valves would function in the same manner, but the piston A would move in the opposite directions according to the open positions of the valves. It is thus seen in The fluid motor element desired.

The speed-responsive canbee centrifuge members.

The governor has a cup-shaped case 1 provided with a cover 2 of suitable non-conducting material. The governor case carries a bracket 3 a motor vehicle.

The shaft 1 of plate 9 on which hers I and II.

the governor is provided with a is pivoted two centrifuge mem- These two centrifuge members centrifuge members fly outwardly, due to increasing speed of the shaft 1 which, of course, would be caused by increasing ,speed driving the shaft. Sleeve l2 has a' short portion l4 extending upwardly therefrom and integral (3 of the governor.

The cover 2 carries the fixed contact it of the switch G and thefixed contact element element the system to be controlled and the terminal l9 having connected thereto the conductor 2| of the circuit Y. The cover of the governor also has pivoted thereon an electrically grounded arm 22 which forms the movable switch element by ing movement of the which the movable contact 23 of the switch G and movable contact 24 oi switch Ci are controlled. The arm 22 is arranged to swing in a plane at right angles to the axis of the governor. Its pivot pin 26 carried by the cover is at one end or the arm and the other end of the arm lies between-the fixed contacts I and I1 and carries the contacts 23 and II. The arm 22 is arranged to be of the snap-over type and to accomplish this there is provided an over-center spring 26 connected at one end to an intermediate portion of the arm and at the other end to the casing and extending across the axis of the pivot pin 25 for the arm. The spring arrangement is such that it will be effective to perform the over-center closcontacts comprising switch G with a "snap action and hold them closed, or to likewise complete the closing of contacts comprising switch G and, once such contacts are closed, to hold them closed until another switching change is inaugurated. v

The moving of the arm 22 to either of the two switch closed positions is accomplished in two merging movements by means of the previously referred to eccentric cam l5 and over-center spring 26. To accomplish this the bottom of the arm carries a downwardly extending pin 21 on one side of the axis of the governor and on the opposite side a flange portion 28 from which extends upwardly a second pin 29. The pins 21 and as have conical ends and these ends are so axlally spaced from each other that it is impossible for the eccentric cam to engage both pins simul taneously. Also the diameter of the cam I5 is less than the distance between the confronting 6 pin as said cam continues to rotate. If the rotative speed of the shaft 1 should become less than a predetermined value, the cam will again cooperate with the pin 23 andopen the contacts of switch G slightly beyond the over-center po"-' sition of arm 22 with respect to the axis of the cam II, and thus [permit] cause the closing of the contacts of switch G solely by the action of the over-center spring 26. The construction of this two-stage governor switch means insures a smooth and quick switch change-over action, since the centrifuge members need only operate the sleeve l2. The movement of the switch controlling arm requires none of the centrifugal force employed for moving the sleeve' l2 axially as the switch moving force comes from the rotation of the sleeve and the action of the over-center spring 26. As a result considerable or all hunting" is eliminated, and also the contact elements can be made sufliciently large to'carry heavy current loads without the necessity of using relay switches in the electrical control circuits X and Y, particularly sustained energized control circuits.

The centrifuge members are arranged to act against a spring means, preferably carried by the cover 2, and to accomplish this the pin H so extends through an arcuate slot in the arm 22 that it can be engaged by a cover carried plunger Ill,

sides of the pins contacted by the cam but having a rise sufficient to throw the arm 22 slightly past the axis of said cam in either direction ofiits movement when either of the switches G or G is closed solely by the action of the over-center spring 26. The associated pin will therefore, be out of the rotative path of the eccentric cam IS. The peripheral portion of the cam is formed with a preferred double beveled surface, as best shown in Figure '1, so as to accommodate [permit] smooth cooperation between it and the conical ends of the pins. 1

When the rotative speed of the driven shaft '1 is below a predetermined value the cam l5 will be in a position to engage pin 25 and consequently the arm 22 will be swung over-center so that the spring 26 can be eifective of switch G with a snap? action, in which position the contacts will be held by the spring as shown in Figures 2, 3 and i. tacts are caused to be closed in the manner above described the pin 29 will be so positioned that it will no longer be able to be contacted by the cam l5 as it rotates with the shaft 1, all as shown in Figures 3 and '7. As the speed of the shaft 1 increases above the predetermined value the cam I! will be moved selectively upwardly by the centrifuge member to a point above the upper end of the pin 28 and will then be in a position to engage the lower end of the pin 21. When this occurs the eccentric cam will swing the arm 22 so as to cause a breaking of the contacts of the switch G and upon the cam moving arm overcenter the spring 26 will effect the actual closing of the contacts of switch G with asnap action and maintain them closed until switch G is again closed. The closed position of switch G is shown in Figures 5 and 6. When the switch G is closed the pin 21 will be positioned sufficiently away from the eccentric cam'that it cannot hit this to close the contacts Once these conwhich plunger is acted upon by a spring 3|, the tension of which may be adjusted by a screw-plug 32. The movable contacts 23 and ll are arranged to be grounded and, as already mentioned, this is accomplished by the conductor Z and a copper strip 33 (Figure 2) which connects the pivot pin of the arm to the governor casing.

My improved speed-responsive device or governor can be employed for other purposes besides closing switches in different circuits. Another example of its use is disclosed in Figures 8 and 9. n As shown in these views, the governor G is adapt ed for directly controlling a valve E to two dif--- ferent operative positions. This valve E, as shown" in Figure 8, is part of a fluid pressure system hav-" ing a double acting fluid motor M provided with sure or vacuum P in a manner similar to the system shown in Figure 1.

The source of pressure P is connected by a con-J duit 3| to the valve E. Between the valve E and one end of the fluid motor is a conduit 35 and between the valve E and the other end of the fluid motor is a conduit 36. The valve E is arranged to alternately connect the conduits 35 and 3S witlir the source of pressure through the conduit The construction of the valve is such that when-i2. one end of the fluid motor is connected to thee fluid source the other end will be connected to at-,'f mosphere. If desired, a hand controlled valve I; can be embodied in the conduit 34 between the source of pressure and the valve E and when this hand valve is closed it will be impossible to operate the fluid motor M, regardless of the condition of the valve E.

The valve E comprises a casing 31 which is attached to the casing l of the governor G adjaf cent the top thereof. This casing is provided. axis at right angles the axis of thegovernor. The ends of the bore} 33 have air openings 39 and 40. Within the bore is a cylindrical slidable valve element ll constructed to have separate passages 42 and U in opposite ends thereof. The passage 42 has ports ll and 45 extending to the periphery of t" e valve element and its outer end closed by a suitable plug l2'. These ports 4| and-l5 are arconcerned. This arm 22' governor is below a sure (suction), thus causing the piston ranged to selectively cooperate with port 46," and 48 in the casing of the valve. The port 48 is in communication with the atmosphere, the port 41 is in communication with the conduit and the port 48 is in communication with the conduit 34. The other passage 43 in the valve element is provided with spaced ports 49 and 50 which extend to the periphery of the valve element and having its outer end closed by a suitable plug 43'. 'l hese ports are arranged to selectively cooperate with ports and 52 and the previously mentioned port 48. Port 5| ls ccnnected to the conduit 36 and port 52 is connected to atmosphere. When the valve element is in the lowermost position, as shown in Figure 8, the ports will be so arranged that the conduits 34 and 35 will be connected to the source of pressure and the conduit 36 will be connected to atmosphere.

When the valve element is moved to its upper position the ports will be so arranged that the conduit 34 will be connected to the conduit 36 and the conduit 35 will be connected to atmosphere. With this arrangement it is seen that if suction isused as a source of pressure the piston of the fluid motor can be caused to move from one end to the other in response to different settings of the valve element.

The valve element is arranged to be controlled by the condition of the governor and to accomplish this the governor is provided with an arm 22' whichis of a construction similar to the previously mentioned arm 22 of the governor shown in Figures 2 to 7, insofar as control structure is has an extension 53 which is arranged to fit into a recess 54 in the valve element. The arm 22' is provided with upwardly extending flanges 23' and 24 which take .the place of the movable contacts 23 and 24 of the switch arm 22 described in Figures 2 to 7 and in place of the fixed contacts of switches G and G of said previously described structure there is provided stops it and I1 carried by the cover 2 of the governor.

When the speed of the rotating shaft 1 of the predetermined value the arm 22' will be swung by the cam l5 and over-center spring 26 in the same manner as the switch arm 22 to the position where the flange 23' engages the stop IE where it will be held by center-spring. This will result in the valve element 4| being placed in its upper position and under such conditions the lower end of the fluid motor M will be connected to the source of pres- A to move to the lower end of the cylinder of the fluid motor. When the speed of the driven shaft rises above the predetermined value the cam element l5 of the speed responsive device will cause the arm 22 to be actuated over-center slightly beyond the axis of the cam and then moved on to the position shown in Figure 8 by the over-center spring 26. Upon completion of the aforesaid movement of arm 22' and connected valve element 4| the spring 23 will be effective to hold said element in its moved operative pcsit'on. When this position is assi med the flange 24' will engage the stop l1 and the valve element 4| will be in the position shown in Figure 8. Under such conditions the upper end of the m id motor will be connect-d to tlesource of suction and the lower end of the fluid motor will be connected to the atmosphere The piston cf the fluid motor w'll therefore be moved to the upper end of the fluid motor cylinder and assume theposltion shown in the over- 'lower end of the Figure 8. If the speed of the driven shaft should assume a value below the predetermined speed, the valve element will again be positioned to cause the piston of the fluid motor to be moved to the fluid motor cylinder. source of pressure is super-atmospheric the piston A will assume opposite positions for the same positions of the valve element.

From the foregoing description of my improved speed-responsive deviceit is seen that it is simple in construction and positive in operation. The arrangement is such that the control of its movable element from one position to another position is quickly and positively made without any tendency of the contact vibrating in closed condition or hunting between different contacts. The actual forces employed in producing the change of the movable contact element from one position to another is directly derived from the torque of the rotating shaft 1 and the over-center action of spring 26. There will be no appreciable resistance to free movement of the centriluge members, thus said members are at all times directly and sensitively responsive to the speed of the rotating shaft. It is also to be noted that the arrangement is such that the actuating cam has some free axial movement between the conical ends of the cooperating pins 21 and 29. Thus, if a pin should be engaged and the contact arm 22 swung from one position to another, it will be swung back in the event the cam should be moved slightly towards the other pin. This is an important feature since it eliminates substantially al huntin'g of the movable contact element between its closed contact positions.

Once the contact arm 22 or 22' is set in a contact operative (closed) position, it will remain fixed in such position until its other operating position is assumed or [and] vice versa. In place of the'arm 22 or 22 having two operative contact positions (closed), eitherof such positions may be an inoperative position (open) in its controlling function.

-In the structure shown, the pins have tapered ends and the cam IS with a double beveled surface. This'is 21 and 29 is provided apreferred cooperation, but is notesscntial. If desired, the tapered ends on the pins and the double beveled surface could be eliminated without affecting the operation of the governor. It the cam'should engage a pin and offer resistance to free movement of the centrifuge members by centrifugal or centripetal forces, such condition would [it will] be only momentary. Due to-[Because of] the eccentric mounting of unable to] contact with a pin cannot occur during approximately eighty percent of any single rotation thereof.

Being aware of the possibility of modifications in the particular structure shown and described without departing from the fundamental principles of my invention, I do not intend that its scope be limited in any manner except in accordance with the appended claims.

What is claimed is:

1. In a speed-responsive device, a rotating shaft, a member to be controlled, means for initiating movement 0] [actuating] said member toward two positions by a direct turning movement of the shaft and comprising a second member slidable on an axis coinciding with that of the shaft, biasing means rendered active for initiation of movement of said first member for completing movement thereof to said two posi- If the the cam, [it will be.

--of its positions -movement only of the cam means.

tions, and movable means responsive to the speed 'of rotation of the shaft for moving said second member axially to cause the controlled member to be selectively actuated as aforesaid, said second member and the movable means being so associated with each other and with said means that the [actuation] completion of movement of the controlled member [will] does not resist free movement ,of the movable means in response to the speed of rotation of the shaft.

2. In a speed-responsive device, a rotating shaft, a member to be controlled, cam means rotatable by the shaft and slidable on an axis coinciding with that of the shaft, said cam means having a portion eccentric to the shaft for selectively actuating said member. toward two positions by the turning movement of the shaft, and means responsive to the speed of rotation of the shaft for sliding the cam means .to cause the controlled member to be directly actuated by the turning of the eccentric portion of the cam means as it is rotated by the shaft.

3. In a speed-responsive device, a rotating shaft, 9. member to be controlled, eccentric cam means rotatable with the shaft and slidable bodily on an axis coinciding with the shaft axis for selectively actuating said member toward two positions by a turning movement of the cam means as it is rotated by the shaft, and means responsive to the speed of rotation of the shaft for selectively determining toward which position the controlled member will be actuated by the eccentric cam means, said last-named means comprising a'member slidable on the shaft and centrifuge members positionedoutwardly of the ,slidable member and operatively connected therewith and to the shaft.

.4. In a speed-responsive device, a member movable to two positions, means for biasing the member in each position, a driven rotatable member, said movable member being movable in a plane at right angles to the axis of the rotatable member-and having parts on opposite sides of said axis, to said rotatable member, means for moving the axially movable member to different positions in response to the speed of the driven rotatable member, and cam means directly rotatable by the rotation of the driven controlled by the axial position of the axially slidable member for selectively engaging the parts of the first-named member which are on opposite sides of the axis of the rotatable member and moving the first-named member from one toward the other by rotative 5. In a speed-responsive device, a pivoted arm movable to two positions, a rotatable shaft, slidable eccentric cam means rotatable by the shaft and having different positions for moving the pivoted arm selectively toward the two positions by the rotation of the cam, centrifuge members controlled by the speed of the rotatable shaft for slidably moving the cam means to its different positions, and means for changing the speed conditions at which the cam means moves the arm comprising a single spring acting at one end on the cam means and an adjustable abutment for the other end of the spring.

6. In a speed-responsive movable to two positions, means for biasing the arm an over-center spring to its two positions, a

device, a pivoted arm its two positions, a rotating cally opposite sides of the shaft axis, an eccentric cam mounted for axial movement on the shaft and rotatable by the shaft, means for selectively moving the arm toward its two positions by the rotation of the cam when it is moved axially to predetermined positions and comprising axially spaced projections on the arm positioned on diametrically opposite sides of the shaft axis and selectively engageable by the cam, and means responsive to the speed of rotation of the shaft for moving thecam axially.

'7. In a speed-responsive device, a pivotedarm movable in a single plane to two positions, an over-center spring means for biasing the arm to shaft having its axis at right anglesto the plane of movement of the arm, an eccentric cam mounted for axial sliding movement bodily on the shaft and rotatable by the shaft, means including projections on the arm positioned on opposite sides of the shaft axis for moving the arm from either position toward the other position by the rotationof the cam, the

direction of movement bein determined by the axial position of the cam, centrifuge members movable in response to the speed of rotation of the shaft, and means for moving the cam axially by the centrifuge members.

8. In a speed-responsive device; a shaft connected to be rotated at varyin speeds; an eccentric cam axially slidable on said shaft and rotatable therewith; centrifuge members rotated by said shaft and operably connected to move said cam to different axial positions in response to varying speeds of said shaft; an arm pivoted to oscillate selectively across the axis of said shaft toward two different positions in a plane substantially at right angles to the axis of said shaft, means for biasing said arm to either of its positions; and means carried by said arm on oppo-.

site sides of said shaft axis and engageable by said cam for directly moving said arm across the axis of said shaft from one position toward the other position, said last-named means and cam being so related that when said cam, is moved axially in one direction past a predetermined point it will engage one of said arm means to 7 thus directly rotate said arm past the axis of said rotating shaft having its axis at right angles to the plane of movement of the arm, axially spaced projections on the arm positioned on diametrishaft toward one-'of said positions, and when moved axially in the opposite direction past a predetermined point said cam will engage the other of said arm means and thus rotate said arm in an opposite direction past the axis of said shaft toward the other of said positions.

9. In a speed-responsive device; a shaft connected to be rotated at varying speeds; an eccentric cam axially slidable on said shaft and rotatable therewith; means responsive to rota-' tion of said shaft and operatively connected to said cam for axially moving said cam to different axial positions in response to varying speeds of said shaft; an oscillatable arm pivoted on an axis parallel to said shaft axis and movable to a single position on opposite sides of a line passing through both of the aforesaid axes; an over-center action spring associated with said arm for completing the movement thereof to either of said positions after said arm has been moved beyond said line; means carried by said arm and positioned on opposite sides of the axis of said shaft, said means being axially spaced apart and so-associated with said cam that with said arm in one position, it will be moved beyond said line toward its other position directly by rotation of said cam when said cam has tioped in one direction past a predetermined been axially posi- 1 12 Po d with d am in its other position it with, an eccentric cam carriedby the axially slidwill be moved beyond said line toward said one able member, centrifuge members rotatable by position directly by rotation of said cam when the shaft and operably connected to move the axially position d in the opp s e direction p s slidable member axially, a member to be coni a trolled and being mounted for selective move- 10. In a speed-responsive device, a rotating ment to two positions, andmeans carried by the shaft, a member to be controlled and capable of member for cooperation with the cam when in movement to two operative positions, eccentric different axial positions [to thereby permit the] cam means selectively slidable on said shaft and whereby said cam by its rotation [to move] selecoperable for directly imparting an initial'movetively moves the member to be controlled to its ment to said member to move-it from either potwo different positions. i iOn tow d h ot Spring means pe t 15. 'In a speed-responsive device comprising a associated with said member for imparting final centrifuge member pivoted to a rotary member movement to Said member in assuming either of fixed on a drive shaft for oscillation between outer said posi i ns. and mean responsive to the speed 15 and inner positions in a. plane disposed substanof rotation only of said shaft for predeterminingv tially at right angles to the plane of rotation of toward which pomtion said member will be inisaid member, and'biased to its inner position by tially moved directly by said cam means when spring means: an eccentric cam axially slidable selectively operated as aforesaid. I on and rotatable with said drive shaft, said cam 11. In a speed-responsive device, a rotating being operatively connected to' said centrifuge shaft, a pivoted arm oscillatable in a plane submember for movement selectively thereby to difstantially at right angles to the axis of said shaft ferent axial positions in response to varying means for moving said arm directly by of said cam in parallel relation to its axis; and a turning movement only of said shaft including means operable for moving said arm toward either rotating cam means having an axis parallel with of its positions by direct selective engagement the pivotal axis of said arm; and means responof said cam with said projections in response to sive to the speed of rotation of said shaft for sethe rotary movem nt and varying speeds of said lectively determining toward which position said rotary member. arm will be initially moved by said rotating cam 16. In a speed-responsive device comprising a when rotated. as centrifuge member pivoted to a rotary member 12. Aspeed-responsive device comprising a rofixed on a drive shaft for oscillation between tary member capable of being rotated at dilfer- .outer and inner positions in a plane disposed subent speeds, a plurality of centrifuge members pivstantially at right angles to the plane of rotation otally attached to said rotary member at diametof said member, and biased to its inner position rically opposite points for movement between in- 40 by spring means: an eccentric cam axially sliddividually operative substantially in unison and cam being operatively connected to said centribeing biased to their inner positions by a single fuge member for movementselectively thereby to spring means; arocker arm movable between two different axial positions in response to varying I extreme positions on opposite sides of and at speeds of said shaft; a pivoted oscillatory arm right angles to th axis of said rotary memb r; movable across the axis of said cam in a plane eccentric cam means mounted for selective axial substantially parallelto its plane of rotation to movement with res ct t s id rotary two operative positions, said arm having axially member and rocker, and operatively connected spaced p fl s Posit on Oppos te sides of by direct engagement of said cam means with rect selective engagement with said pro c io s said roclrer in res use to rotation only of said whereby said over-center spring means is renrotary member. dered eilective to complete the movement of said 13. In a speed-responsive device, a rotatable rm to he s le ed Op a i p s shaft, a pivoted arm for swinging movement in 17. A speed-responsive device comprising a roa plane at right angles to the axis of-the shaft, tary member capable of being rotated at differ move the arm by rotation of the cam, and means Tl responsive to the speed of rotation of the shaft said rocker having operatively associated therefor moving the cam axially. i with over-center action spring means; eccentric 14. In a speed-responsive device, a rotatable cam means mounted for selective axial sliding shaft. a member axially slidable on [the end of] movement with respect to said rotary member the shaft and rotatable [with the shaftj there- 7- and rocker, and operatively'connected to said positions with said rocker;

13 members; means responsive to the movements of said members when rotated at different speeds for sliding said cam means selectively to engaging means operable to .ini-

18. In a speed-responsive device, a rotary shaft,

a member to be controlled, means comprising a rotating cam rotated by the shaft for selectively actuating the member toward two positions by the turning movement of the cam, means comprising a centrifuge member movable by the speed of the rotatingshait for determining toward which position the actuating means will move the member to be controlled, and adjustable means for varying the determining condition comprising a single spring separate from the centrifugal member and acting on the actuating 5 REFERENCES CITED The following references are of record in the file oi. this patent or the original patent: UNITED STAT S Parents 10- Number Name Date 625,363 Smith May 23, 1899 660,047 Conklin Oct. 16, 1900' 791,694 Hudson June 6, 1905 1,370,749 Kimble Mar. 8, 1921 15 1,401,587 Cornwall Dec. 27, 1921 1,419,626 Hardin June 13, 1922 1,680,944 Hoglund Aug. 14, 1928 2,083,343 Naul June 8, 19 7 2,164,667 Sinnett July 4, 1939 20 2,338,859 Livingston Jan. 11, 1944 FOREIGN PATENTS Number Country Date means. and an adjustable member for varying the tension or the spring.

GLENN T. RA NDOL.

Great Britain Jan, 24, 1861 

